NFS: use scope from exchange_id to skip reclaim

can be skipped if the "eir_server_scope" from the exchange_id proc differs from
previous calls.

Also, in the future server_scope will be useful for determining whether client
trunking is available

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

7 files changed, 55 insertions, 2 deletions

diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index b3dc2b88b65b..006f8ff0a3c0 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -293,6 +293,7 @@ static void nfs_free_client(struct nfs_client *clp)
         nfs4_deviceid_purge_client(clp);
 
         kfree(clp->cl_hostname);
+        kfree(clp->server_scope);
         kfree(clp);
 
         dprintk("<-- nfs_free_client()\n");
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index c4a69833dd0d..b47f0d4710fa 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -48,6 +48,7 @@ enum nfs4_client_state {
         NFS4CLNT_SESSION_RESET,
         NFS4CLNT_RECALL_SLOT,
         NFS4CLNT_LEASE_CONFIRM,
+        NFS4CLNT_SERVER_SCOPE_MISMATCH,
 };
 
 enum nfs4_session_state {
@@ -349,6 +350,8 @@ extern void nfs4_schedule_state_manager(struct nfs_client *);
 extern void nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
 extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags);
 extern void nfs41_handle_recall_slot(struct nfs_client *clp);
+extern void nfs41_handle_server_scope(struct nfs_client *,
+                                      struct server_scope **);
 extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
 extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
 extern void nfs4_copy_stateid(nfs4_stateid *, struct nfs4_state *, fl_owner_t, pid_t);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 5879b23e0c99..5f4912f72282 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -4781,6 +4781,16 @@ out_inval:
         return -NFS4ERR_INVAL;
 }
 
+static bool
+nfs41_same_server_scope(struct server_scope *a, struct server_scope *b)
+{
+        if (a->server_scope_sz == b->server_scope_sz &&
+            memcmp(a->server_scope, b->server_scope, a->server_scope_sz) == 0)
+                return true;
+
+        return false;
+}
+
 /*
  * nfs4_proc_exchange_id()
  *
@@ -4823,9 +4833,31 @@ int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred)
                                 init_utsname()->domainname,
                                 clp->cl_rpcclient->cl_auth->au_flavor);
 
+        res.server_scope = kzalloc(sizeof(struct server_scope), GFP_KERNEL);
+        if (unlikely(!res.server_scope))
+                return -ENOMEM;
+
         status = rpc_call_sync(clp->cl_rpcclient, &msg, RPC_TASK_TIMEOUT);
         if (!status)
                 status = nfs4_check_cl_exchange_flags(clp->cl_exchange_flags);
+
+        if (!status) {
+                if (clp->server_scope &&
+                    !nfs41_same_server_scope(clp->server_scope,
+                                             res.server_scope)) {
+                        dprintk("%s: server_scope mismatch detected\n",
+                                __func__);
+                        set_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state);
+                        kfree(clp->server_scope);
+                        clp->server_scope = NULL;
+                }
+
+                if (!clp->server_scope)
+                        clp->server_scope = res.server_scope;
+                else
+                        kfree(res.server_scope);
+        }
+
         dprintk("<-- %s status= %d\n", __func__, status);
         return status;
 }
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index e97dd219f84f..5d744a52b4e1 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -1643,7 +1643,14 @@ static void nfs4_state_manager(struct nfs_client *clp)
                                 goto out_error;
                         }
                         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
-                        set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
+
+                        if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH,
+                                               &clp->cl_state))
+                                nfs4_state_start_reclaim_nograce(clp);
+                        else
+                                set_bit(NFS4CLNT_RECLAIM_REBOOT,
+                                        &clp->cl_state);
+
                         pnfs_destroy_all_layouts(clp);
                 }
 
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index e6e8f3b9a1de..1555c74dd336 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -4977,11 +4977,17 @@ static int decode_exchange_id(struct xdr_stream *xdr,
         if (unlikely(status))
                 return status;
 
-        /* Throw away server_scope */
+        /* Save server_scope */
         status = decode_opaque_inline(xdr, &dummy, &dummy_str);
         if (unlikely(status))
                 return status;
 
+        if (unlikely(dummy > NFS4_OPAQUE_LIMIT))
+                return -EIO;
+
+        memcpy(res->server_scope->server_scope, dummy_str, dummy);
+        res->server_scope->server_scope_sz = dummy;
+
         /* Throw away Implementation id array */
         status = decode_opaque_inline(xdr, &dummy, &dummy_str);
         if (unlikely(status))
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 87694ca86914..f23b18831559 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -16,6 +16,7 @@ struct nfs4_sequence_args;
 struct nfs4_sequence_res;
 struct nfs_server;
 struct nfs4_minor_version_ops;
+struct server_scope;
 
 /*
  * The nfs_client identifies our client state to the server.
@@ -83,6 +84,8 @@ struct nfs_client {
 #ifdef CONFIG_NFS_FSCACHE
         struct fscache_cookie   *fscache;       /* client index cache cookie */
 #endif
+
+        struct server_scope     *server_scope;  /* from exchange_id */
 };
 
 /*
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index 00848d86ffb2..c4d98df884f3 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -1060,6 +1060,7 @@ struct server_scope {
 struct nfs41_exchange_id_res {
         struct nfs_client               *client;
         u32                             flags;
+        struct server_scope             *server_scope;
 };
 
 struct nfs41_create_session_args {